Recently, image forming apparatuses, each of which accommodates respective functions of various devices such as a printer, a copier, a facsimile and a scanner in one housing thereof, are widely known. Such a compound type image forming apparatus includes a displaying part, a printing part and an imaging part in one housing but also respective applications corresponding to a printer device, a copy device, a scanner device and a facsimile device, and by switching the applications, the image forming apparatus can be made to operate as a printer device, a copy device, a scanner device and a facsimile device.
However, as the Internet is widely used and a variety of communication protocols are designed, the market requires that a conventional compound type image forming apparatus having a printer function as mentioned above be able to meet printing requests delivered from various types of interfaces. In such a conventional compound type image forming apparatus, whenever a new interface is added, the image forming apparatus is individually capacitated to meet such a market need. In the case of individual capacitation, it is necessary to modify installed applications so that these applications can deal with a newly added interface. On the other hand, if an application is newly developed and installed, there is a problem that the application has to be developed to have compatibility with a plurality of interfaces.
Also, since the recent development and popularization of the Internet make such a conventional compound type image forming apparatus having a printer function that can communicate via a network connectable to other devices via the network, the image forming apparatus is expected to provide a Web service that can be served under communication control in accordance with a communication protocol for the Internet, that is, HTTP (Hypertext Transfer Protocol). In addition to the communication control in accordance with HTTP, furthermore, it is required to cause each application of a conventional compound type image forming apparatus to perform operations caused by differences of methods specified in HTTP and XML descriptive operations so that the applications to execute image forming operations can communicate messages under a tendency to widen the coverage of connected devices by describing a general-purpose description format such as XML (extensible Markup Language) in the body part of HTTP. Accordingly, developers that develop an application corresponding to a Web service are required to develop a function-by-function program.
In the conventional compound type image forming apparatus, if each application provides an image forming process as a Web service via a network, it is necessary to modify the installed application so that the description format of messages communicated in accordance with a network protocol can be interpreted. Also, in a case where the description format of the messages is XML (eXtensible Markup Language), if applications developed in accordance with a conventional development method are modified corresponding to a Web service or if an application corresponding to a Web service is newly added to the conventional compound type image forming apparatus, it is difficult to develop an application in accordance with a conventional development method because of requirement of XML knowledge to the developers.
As mentioned above, since the data format of a message in accordance with XML is different from the data format processable in a program language for a Web service function, it is necessary to provide a scheme to absorb the difference between the two data formats in each Web service function. In the development of such a scheme to absorb the data format difference, a large number of simple and similar codes have to be repeated, and there is a problem in that bugs due to simple errors may be contained easily.